Piston-pin lock



R. O. WATSON.

PISTON PIN LOCK.

.APPLICATION FILED MAY 20, 1919.

Patented June 14, 1921.

ATTORNEY f2? QZENTOR RALPH 0. warson, or JERSEY crrr, NEW .rnnsmr.

.IPISTON-PIN LOCK.

Specification of Letters Patent.

Patented June 14, 1921.

Application filed May 20, 1919. Serial No. 298,522.

I T all whom z'tmag] concern,

Be it known that I, RALPH O. WATSON, a citizen of the United States, residing at Jersey City, in the State of New Jersey have invented certain new and useful Improvements in Piston-Pin Locks, fully described and represented in the following specification and the accompanying drawing, forming a part of the same.

A principal object of my invention is to provi e very simple and secure means for retaining the piston pin in proper position in a piston. Another object is to provide locking means which are equally effective with a piston pin which is free to rotate in the piston or is secured therein against rotation. A further locking device which is located inwardly from the outer piston surface, and there-v fore cannot engage the cylinder wall; which retains the pin in such a way that the ends of the pin cannot touch the cylinder wall, and which is self-retained in position in the piston.

The accompanying drawing shows an exemplifying embodiment of the invention.

Figure 1 is a vertical section of a structure embodying the arms of the pin.

Fig. '2 is a Vertical a right angle to that 1g. 3 is a side the end of the pin.

Fig. 4 is a horizontal section in the plane of the pin axis.

The reference character 1 designates a trunk piston having the usual holes 2 in opposite side walls to receive the pin 3. The material of the piston is extended inwardly as usual to provide sleeves 4 supported by webs 5, so that the pin has ample area of contact with the piston. An annular groove 6 is formed in the piston wall, and for the proper accommodation of this groove the wall is preferably provided with an annular inner enlargement 7. At a reasonable distance inwardly from the outer surface of the piston at least one undercut oove 8 is formed extending at a right ang e to the direction of groove 6, and usually there are two of these undercut grooves as shown. Grooves 6 and 8 intersect the outer ends of section in a plane at of Fig. 1.

the piston pin holes 2. After the pin is put in position, split at 10, is grooves 8,

the locking ring 9, which is inserted in the undercut and when so inserted, lies outobject is to provide a 7 'ing of the cylinder wall or of the the invention, in the plane of elevation looking toward I side the ends of the pin and positively prevents the pin from coming in contact with the walls of the cylinder and is self-retamed in position out of contact with the cylinder walls.

The locking ring pulling it open somewhat, passing it over the end of the piston and bringing it down opposite the groove 6 and then inserting one of its ends into the outer end'of one of the pin holes 2 and into the ends of undercut grooves 8 where they enter the hole; then pushing the end of the ring around through the undercut grooves until the other end of the ring snaps into the pin aperture; and then if desired the ring may be rotated still farther until it assumes such a position as shown in Fig. 3, in which the split 10 is out of registry with the pin apertures.

.It is usually desirable to provide means such as holes .11 near the ends of the locking ring by which a tool may be easily used to insert or remove the rin It will be noted that this locking device does not affect in any way the normal,,oil-

piston pin, nor does it afi'ect the wiping of the cylinder walls by rings or other devices which may be employed for that purpose in accordance with the standard practice. The invention is also equally adapted to an arrangement in which the pin 3 is free to turn in the sleeves 4, or one in which the pin is made with such a close fit that it will not turn in the piston.

The engagement of the edges of the looking ring with the undercut grooves 8 positively prevents the ring from being extended by endwise movement of the plston pin, or from any other cause. In some cases it will.be evident that a single undercut groove extending from one side of the bottom of groove 6 will be sufiicient for this purpose.

at is claimed is:

1. A piston structure, comprising in combination with a piston having a transverse opening and a piston pin in said opening, a retaining ring passing about the piston opposite the ends of the pin and having its outer surface located inwardly from the outer piston surface, and positive means holding the retaining ring in position away from contact with the cylinder wall.

2. In a piston structure, the combination with a piston having transverse holes in two is easily inserted by opposite sides and a piston pin located in ring having near one of its ends a hole to the holes, of locking means comprising a receive a tool for manipulating the ring.

split ring encircling the piston and inter- 5. In a piston construction, the combina 35 secting said holes at points substantially option of a piston having in opposite sides posite the ends of the, pin, said ring being holes to receive the piston pin, and having secured in a vertically undercut portion of a groove intersecting the outer portionscf a groove surrounding the piston, said undersaid holes, the groove being provlded with cut portion being located inwardly from the vertically undercut extensions located con- .40

outer surface of the piston. siderably inwardly from the outer surface 3. In a piston construction, the combinaof the piston, a piston pin located in said tion of a piston having in opposite sides holes, and a divided locking ring located in holes to receive the plston pin, and having" the undercut portions of said groove, the a roove intersecting the outer portlons of ring having near its ends holes to receive a 45 vsaid holes, the groove belng provided with tool for manipulating the ring.

vertically undercut extensions located con- 6. In a piston construction, the combinasiderably inwardly from the outer surface tion of a piston having in opposite sides of the piston, a piston pin located in said holes to receive the piston pin, and'having a holes, and a divided locking ringlocated in groove intersecting the outer portions of 50 the undercut portions of said groove, the said holes, the groove being provided with a ring having near its divided portion means vertically undercut extension located conadapted to be engaged by a tool for manipusiderably inwardly from the outer surface lating the ring. of the piston, a piston pin located in said 4. In a piston construction, the combinaholes, and a divided locking ring located in 55 tion of a piston having in opposite sides th undercut portion of said groove.

holes to receive the piston pin, and having a In testimony whereof I have hereunto set groove intersecting the outer portions of my hand in the presence of two subscribing said holes, th; groove being prlovided1 with witnesses.

vertically un ercut extensions ocate con- 1 siderably inwardly from the outer surface RALPH WATSON of the piston, a piston pin located in said Witnesses: holes, and a divided locking ring located in ADELE S. EBERHARDT,

the undercut portions of said groove, the MAISIE MAURUS. 

